Rapid advances in communication technology have made it possible for a mobile user to have any conversations or send a text message while moving. Mobile communication terminals such as mobile phones, PDAs, pocket PCs and Internet terminals now have a wide range of applications.
Particularly, technical advances in a wireless personal communication service and a sharp increase in the number of subscribers to the service have prompted various kinds of additional services, which are currently available.
Among those additional services is the text-message transmission service through a (voice) communication terminal. Because of its convenience, many subscribers have been using the service.
The text-message transmission is made it possible through a miniature keyboard such as an electronic keypad to which a subscriber inputs a message to be sent.
The miniature keyboard have a wide range of applications, including Palm Top computers, Internet TVs, digital still cameras, PDAs, electronic organizers, kiosks for use in public buildings and other places in need of guidance, electronic keys, ATMs and so forth.
To be able to provide the text-message transmission service involving the miniature keyboard with a limited number of buttons such as an electronic telephone keypad, it is very important to arrange on the keypad consonants/vowels of a language to be supported in such a manner that a user is able to find desired letters more quickly and combine consonants and vowels more easily by operating the functional keys available.
A number of attempts have been made to meet the afore-mentioned technical needs, but the conventional techniques relevant to the character input schemes using the electronic telephone keypad could not satisfy such needs. For example, consonant and vowels on the keypad were randomly mixed together, so it took a long time for users to memorize where the characters are located. In addition, users had to input a period mark every time a letter was complete, which was another inconvenience to most of them.
Although recently developed devices and methods for text input solved some of the existing problems, manufacturers are still hesitating on whether to produce those new devices because cost of manufacture was considerably increased and technical problems causing inconvenience to users were not completely resolved yet.
On the other hand, X-coordinate, X Y-coordinate, and consecutive push input systems being currently used in PCS have many problems. For instance, to create a text message users have to use not only a separate mode conversion button but also functional keys including arrow keys. That is, a large number of key input operations are required and needless to say, it took a long time for the users to read coordinates on the keypad.
In addition, the related art character input methods using the electronic telephone keypad have a very different input system from that of typical word processors, whereby many users were often frustrated for operating keys. Especially, in case that a plurality of consonants and vowels are assigned to a single button, no matter how well organized the characters are, it takes much efforts and time to learn the positions of characters and the key operations.
The importance and role of the proper methods and apparatuses for inputting characters in a mobile communication terminal will be magnified by the fact that in next generation image mobile phone businesses IMT-2000 terminals will soon be used in wireless network making it possible for users to communicate data over very high speed wireless Internet. Therefore, to use a mobile communication terminal as an ideal compound multimedia equipment as many users now hope, it would be highly advantageous to provide methods and an apparatus for inputting characters in a mobile communication terminal that overcome the disadvantages and limitations found in the existing displays and input systems.